The surface-emitting quantum cascade laser lases in the TM (transverse magnetic) mode and emits laser light with wavelengths from infrared to terahertz.
The optical resonator can be configured from a two-dimensional photonic crystal provided near the active layer.
The surface-emitting quantum cascade laser including a two-dimensional photonic crystal is operated as a laser of the surface emission type capable of emitting laser light in a direction generally perpendicular to the surface of the active layer.
In a structure including the current injection part and the photonic crystal part in the same region, increasing the operating current to obtain high output power results in raising the chip operating temperature. This increases the change of refractive index of the photonic crystal part and degrades optical characteristics.